Monday, March 2, 2015

A paper published in the AGU journal Reviews of Geophysics utilizes the second law of thermodynamics principle of maximum entropy production to accurately determine the meridional and vertical temperature profiles of the atmosphere and Earth surface without incorporating concentrations of any greenhouse gases or greenhouse gas radiative forcing that form the basis of the catastrophic anthropogenic global warming (CAGW) radiative greenhouse theory. The paper (and several others cited by the paper) corroborates the underlying physical assumptions of the Maxwell/Carnot/Clausius atmospheric mass/gravity/pressure theory of the 33C greenhouse effect and the 'greenhouse equation.'The conventional CAGW radiative greenhouse theory assumes greenhouse gas backradiation from the lower temperature/frequency/energy atmosphere is capable of warming by 33C the higher temperature/frequency/energy Earth surface. The 2nd law of thermodynamics requires heat to flow one-way only from hot to cold, and total system entropy to increase to the maximum potential extent. However, net heat flow from a cold atmosphere necessary warm the hot Earth surface by 33C would require an impossible decrease of total system entropy, forbidden by the 2nd law and principle of maximum entropy production. Although radiation between hot and cold bodies is bidirectional, the 2nd law only permits heat to flow one-way from a higher temperature/frequency/energy body to a lower temperature/frequency/energy body.

JC comments:The 2nd law of thermodynamics is an underutilized piece of physics in climate science. It is not a simple beast to wrestle with, but I think there are some important insights to gain. Optimality, self-organizing criticality, and nonlinearity are factors that are not adequately accounted for in traditional climate feedback analyses, and an entropy-based framework would be more consistent with the climate shifts that are actually observed.

Inspired by the famous engineer/physicist Carnot's description of the atmosphere as a heat engine (which also forms the basis of the Maxwell/Carnot/Clausius atmospheric mass/gravity/pressure theory of the 33C greenhouse effect), the authors develop an Earth energy and entropy budget and simple climate model on the basis of the second law of thermodynamics and principle of maximum entropy production (MEP).

"The opening words of Carnot s original treatise on
thermodynamics provide a good starting point for this
review paper. We consider that Carnot 's view contains
invaluable insight into the subject, which seems to have
been lost from our contemporary view of the world.
Carnot regarded the Earth as a sort of heat engine, in
which a fluid like the atmosphere acts as working substance
transporting heat from hot to cold places, thereby
producing the kinetic energy of the fluid itself. His
general conclusion about heat engines is that there is a
certain limit for the conversion rate of the heat energy
into the kinetic energy and that this limit is inevitable for
any natural systems including, among others, the Earth s
atmosphere. His suggestion on the atmospheric heat
engine has been rather ignored. It is the purpose of this
paper to reexamine Carnot s view, as far as possible, by
reviewing works so far published in the fields of fluid
dynamics, Earth sciences, and nonequilibrium thermodynamics."

As illustrated in Fig 5 below, the author's entropy & energy budget shows heat flows one-way only from hot to cold, and there are no terms for greenhouse gases, backradiation, or radiative forcing from greenhouse gases incorporated anywhere in the author's energy and entropy budget calculations. The author's energy budget is in stark contrast to Trenberth's energy budget showing 333 W/m2 of greenhouse gas backradiation from the cold atmosphere heating the Earth surface (alleged to be more than double the radiative input from the Sun absorbed at the Earth surface [161 W/m2]).

Figures in [brackets] are in W/m2, figures without brackets are temperatures Ts= surface temperature, Tsun = sun surface temperature, Ta= equilibrium temperature of the atmosphere = 255K, S= various entropy components of the system. The sequence of heat flow is one-way only from Sun to Earth to atmosphere to space. Meridional transport of heat from the hot equator to the cold poles by winds and oceans is illustrated by the circular arrows. Note the author's analysis of the entropy budget incorporates the entire universe, as the only truly "closed thermodynamic system" is the universe itself, and for which total system entropy must always increase according to the 2nd law.

On the basis of this simple energy/entropy model assuming maximum entropy production (and no warming or radiative forcing from greenhouse gases), the authors find a remarkable agreement between modeled and observed temperatures, fractional cloud cover, and meridional heat flux from the equator to the poles:

[1] The long-term mean properties of the global climate system and those of turbulent fluid systems are reviewed from a thermodynamic viewpoint. Two general expressions are derived for a rate of entropy production due to thermal and viscous dissipation (turbulent dissipation) in a fluid system. It is shown with these expressions that maximum entropy production in the Earth's climate system suggested by Paltridge, as well as maximum transport properties of heat or momentum in a turbulent system suggested by Malkus and Busse, correspond to a state in which the rate of entropy production due to the turbulent dissipation is at a maximum. Entropy production due to absorption of solar radiation in the climate system is found to be irrelevant to the maximized properties associated with turbulence. The hypothesis of maximum entropy production also seems to be applicable to the planetary atmospheres of Mars and Titan and perhaps to mantle convection. Lorenz's conjecture on maximum generation of available potential energy is shown to be akin to this hypothesis with a few minor approximations. A possible mechanism by which turbulent fluid systems adjust themselves to the states of maximum entropy production is presented as a self-feedback mechanism for the generation of available potential energy. These results tend to support the hypothesis of maximum entropy production that underlies a wide variety of nonlinear fluid systems, including our planet as well as other planets and stars.Related:

2 comments:

"in stark contrast to Trenberth's energy budget showing 333 W/m2 of greenhouse gas backradiation from the cold atmosphere heating the Earth surface (alleged to be more than double the radiative input from the Sun absorbed at the Earth surface [161 W/m2])."

I have previously noticed that Trenberth omits the thermal effect of adiabatically warming descending air (50% of the atmosphere at any given moment) and then has to propose back radiation as a warming element in order to balance the energy budget.

Quandam & others might be interested in this paper which derives a simple climate model and energy/entropy budget on the basis of the 2nd law/ principle of maximum entropy production & Carnot equation

http://www.knmi.nl/~laagland/cursus/presentaties_voorjaar11/Ozawa.pdf

fig 5a energy budget diagram is entirely missing Trenberth’s 333 W/m2 ghg back radiation, but shows the 40 W/m2 direct radiative atmospheric window to space (same as Trenberth) and 102 W/m2 convection of latent & sensible heat from the surface to TOA (almost same as Trenberth’s 97 W/m2). Thus, convection greatly dominates heat transport from the surface to tropopause, and is more than twice the magnitude of radiative transport through the atmospheric window. The authors close their energy & entropy budgets without any determination of IR surface back radiation from GHGs, greenhouse gas concentrations, or radiative forcing from GHGs.